Field of the Invention
The present invention relates to microneedle units having microneedles.
Discussion of the Background
Transdermal absorption is a method of administering a substance into the body by infiltrating the substance such as a drug into the body through the skin. Transdermal absorption is also a convenient method of administering a substance into the body without causing pain to an administration target such as a human.
In the transdermal absorption method, it has been proposed to administer drugs into the skin by piercing a microneedle into the skin. The microneedle includes a projection with a size that does not provoke pain in the administration target. The projection is configured to penetrate through the stratum corneum, which is a barrier layer of the skin. As the drug is absorbed into the skin through a hole created in the skin by the microneedle, the drug is percutaneously absorbed (for example, see PTL 1).
PTL 1: WO 2008/020632